Aerial view of State Highway 2 of the Horokiwi Quary and the Petone Interchange.

Earthquakes prompt a fresh look at Petone to Grenada Link Road

December 2017

The New Zealand Transport Agency is re-examining the Petone to Grenada (P2G) Link Road project to ensure the project will deliver the best possible outcomes, particularly in terms of resilience to major events such as earthquakes and storms.

“In mid-2017 NZTA established a detailed evaluation of the current P2G design to determine how it would perform in terms of resilience, following what we learnt from the Kaikoura and Wellington earthquakes,” Director Regional Relationships Emma Speight says.

“It is of the utmost importance to NZTA that Wellington’s critical transport lifelines are as resilient as possible to major events, so we applied a very critical eye to P2G.”

“We have also reviewed the expected costs, benefits and environmental impacts. The findings have resulted in the Agency now revisiting some key design assumptions that underpinned the development of the P2G preferred alignment.”

The evaluation found that:

the current alignment may not provide the lifeline resilience outcomes first anticipated because the very high “vertical cuts” would be susceptible to landslides following a major (7.5 magnitude) earthquake

the project objectives may not reflect the high priority now being placed on resilience by local and central government

expected costs could be significantly higher than first anticipated

environmental impacts of the current scheme may be difficult to mitigate.

“We will now work with the local councils to review the project objectives. Together we will reconsider the need for an expressway standard, examine some of the discarded options and explore how the project could enhance and promote public transport and cycling,” Ms Speight says.

“The communities affected by the project also need to be part of this conversation. Once we’ve agreed with councils on the project objectives, we’ll talk with the community about the project’s next steps and the opportunities they will have to provide input.”

“The additional investigation and discussions with councils will take time. We realise that uncertainty caused by the delay can be frustrating for people affected by the project such as property owners and we thank them for their continued patience.”

A new project timeline will be released in early 2018. More information about the P2G Link Road and the project evaluation findings can be found here.